Time-cost computer



Nov. 17, 1959 J. J. STEDELIN, JR, ETAL TIME-COST COMPUTER Filed Sept. 4,1956 3 Sheets-Sheet 2 z W m 4% I 54M, 1 2 Z Jim f 3 Z 3 M Nut UnitedStates Patent TIME-COST COMPUTER Jerome J. Stedelin, Jr., St. Louis, andGeorge A. Seaton, Normandy, Mo.

Application September 4, 1956, Serial No. 607,718 Claims. (Cl. 235-613)This invention relates to time-cost computers, and more particularlyapparatus of the type in which a card is marked either by punching or byapplying conductive matter or ink so as to indicate the beginning of atime interval. The marking on the card is then later read electricallyand used to actuate an indicating display arranged to show the price ofthe services corresponding to the time interval elapsed. Moreparticularly, our invention is useful in computing and displaying thecost of parking fees or of the labor of a mechanic, or of any otherservice in which the price of the service depends on the number of timeintervals consumed such as hour, hours, or the like. Previous computersof the time-cost type have been proposed in many versions, but all havebeen too bulky and delicate, and consequently too expensive forwide-spread use, because they have attempted to compute the timeinterval elapsed with a degree of precision unnecessary for many commonapplications.

It is therefore the purpose of our invention to provide a simple andrugged device for computing and displaying the cost of servicesdepending on the number of time intervals elapsed.

It is a further object of this invention to provide an apparatus whicheliminates manual computation of the cost of certain services, and thuseliminates the error inherent therein.

We shall now explain the functioning of our device, reference being hadto the accompanying drawings in which:

Figure 1 is an overall view of our device as it would appear wheninstalled;

Figure 2 shows the detail construction of one embodiment of the timingdevice and marking and switching mechanism associated therewith;

Figure 3 is a detail of one embodiment of our sensing device; and

Figure 4 is a partial wiring diagram of our device.

Figure 2 shows a clock or a timing device 10 in the form of a smallsynchronous motor which drives earns 12 and 14 through shaft 16. In theembodiment described herein, cam 14 is provided with ten pins 18 ridingagainst a switch 20 in such a manner as to close switch 20 every *SiXminutes, clock 10 and shaft 16 being so arranged that 'shaft 16 makesone revolution every hour. Cam 12 is provided with only a single pin '22which engages a microswitch 24 and consequently closes microswitch 24once every hour. Switch 20 controls solenoid 26 which by means of hook28 advances ratchet wheel 30 one step each time it is energized. Ratchetwheel 30 has ten teeth. Spring 32 returns hook 28 into positionalongside the next tooth of ratchet wheel 30 when solenoid 26 is againdeenergized. Ratchet wheel 30 is in turn fastened to shaft 34 on whichis mounted gear 36 which engages a gear 38 mounted on a shaft 40 in a1:1 ratio. A member 42, which may be either a spring detent or a rotaryswitch as will be more fully hereinafter described, is also mounted onshaft 34.

Shaft 40 is provided at its lower end with an arm 44 provided at itsouter end with a presser head 46. Located directly beneath the path ofpresser head 46 are ten plungers 48 urged upward by springs 50 andadapted for vertical movement in appropriate bores of a supportingmember 52. The lower ends of plungers 48 are sharpened so that when acard 54 is interposed between support member 52 and base plate 56, thedepressed plunger 48 will cut a hole in card 54. The material punchedout of card 54 is ejected from the machine through bores 58 in baseplate 56. In a similar manner, switch 24 opcrates a relay 60 whichengages ratchet wheel 62. Ratchet wheel 62, which has twenty-four teeth,is mounted on shaft 64 and is connected to a spring detent or switch 66.Shaft 68 is driven from shaft 64 through 1:1 ratio gears 70 and 72. Anarm 74 is mounted at the lower end of shaft 68 and is provided with apresser head 76 which actuates one of twenty-four plungers 48 disposedwithin supporting member 52 in a second ring concentric with the ring ofplungers actuated by arm 44.

It is to be understood, of course, that it is a matter of design whichshaft the parts are mounted on, what the teeth numbers and gear ratiosare, or how motion is transmitted from one shaft to another, and theabove is cited as an example only.

A microswitch 78 is so arranged between the supporting member 52 and thebase plate 56 that it will be closed when card 54 is fully insertedbetween the supporting member and the base plate. The closing of switch78 0perates solenoid 80 momentarily, until the closing of delay relay8'2 reopens its circuit. As solenoid 80 is energized, arm 84 moves todepress both the shafts 40 and 68, whereby presser heads 46 and 76engage the pins 48 above which they happen to be positioned at thatmoment and depress these pins 48 so as to punch two holes indicative ofa given time into the card 54. After the momentary energization ofsolenoid 80, spring 86 returns arm 84 and shafts 40 and 68 to their restpositions. Delay relay 82 is so constructed as to close about A secondafter being energized and is provided so as to open the circuit ofsolenoid 80 after its initial operation and until switch 78 is reopenedby the withdrawal of card 54, in order to avoid double punching. Relay88 is provided to prevent the ratchet wheels from advancing during apunching operation.

If the card punching device is to be used separately from the read-outand indicating device, elements 42 and 66 may be so arranged as to havea detent function only, in order to center the presser heads accuratelyover each plunger 48. However, if the punching mechanism is to beincorporated in the same unit with the read-out and indicating device,elements 42 and 66 can be provided in the form of rotary switches whichwill then become respectively the switching devices 42 and 66 in Figure4. The normal detent action of the rotary switches could then be used toprovide the necessary detent function. If desired, ratchet wheels 30 and62 may also be geared to appropriate counters 90 (Figure 1) so that thetime of the punching operation may be continuously indicated in anindicator window 92 provided in the housing 94 of the device.

If the sensing unit is to be used alone and is not to be provided with apunching unit, it must of course be provided with its own timer 10,ratchet wheels 30 and 62, and switches 42 and 66, operated in the samemanner as hereinabove described.

Figure 3 shows a sensing device which may be used in one embodiment ofour invention. The sensing device is composed of an insulating barrel102 in which are mounted two concentric rings of contact fingers 104 and106 corresponding to the two rings of plungers 48 in Figure 2. Thebarrel 102 is so supported that its contact fingers are normally spacedfrom the base plate 108. When a card 54 is inserted in guide 110 of thebase plate 108, it closes switch 112 upon full insertion. This actuatessolenoid 114 and delay relay 116, the latter being so constructed thatit will close about three seconds after switch 112 has closed. Solenoid114, when energized,

brings barrel 102 down on card 54 by means of the lever 118. The card 54keeps the contact fingers insulated from base plate 103 except at thepoints where holes have previously been punched into the card. Stop 120,actuated by solenoid 122 through lever 124, prevents withdrawal of thecard 54 until delay relay 116 closes, to prevent movement of the carduntil the reading operation has been completed. A relay 126 is providedto close concurrently with solenoids 114 and 122, for a reason to behereinafter explained.

Referring now to Figure 4, there is shown therein a number of seriesconnected resistors forming the resistor banks 202, 204, and 206. Banks202 and 204 are each composed of nine equal resistors 208, each of whichhas a resistance value of one unit. Bank 206 is composed of twenty-threeequal resistors 210, each of which has a resistance value equal to tenunits. A single resistor 212 of a resistance value approximately equalto one hundred units is connected between resistor bank 206 and thenegative side 214 of a suitable D.C. supply 216. The positive side 218or" the DC. supply 216 is connected to the top 220 of resistor bank 202.Switches 42 and 66 are so arranged as to short out a given number ofresistors in banks 202 and 206, respectively, according to the time ofday at the moment of actuation of the sensing device. Sensing rings 104and 106 of sensing device 100 are so arranged as to short out a certainnumber of resistors in banks 204 and 206 according to the time punchedon the card 54. A potentiometer 222 and a resistance 224 are connectedin parallel with resistor banks 202, 204, 206, and resistor 212. A wire226 is connected from a point 228 between the bottom of resistor bank206 and the top of the large resistor 212 through the contacts 230 ofrelay 126 to one side of the input to a vibrator 232 synchronized withthe 110-volt AC. power line (not shown). The other side of the input ofthe vibrator 232 is connected through wire 234 to the slider 236 ofpotentiometer 222.

The vibrator 232 chops up the DC). input voltage applied to it andproduces at its output 237, 233 an AC. signal of a voltage proportionalto the D.C. input voltage. This permits the use of an A.C. amplifier 240for amplifying the signal appearing at 237, 238 and feeding it to thecontrol winding 242 of a s'ervomotor 244. It is to be understood, ofcourse, that vibrator 232 and A.C. amplifier 240 could be replaced by aDC. amplifier if desired, or that the entire circuit could be operatedwith A.C. The servomotor 244 drives shaft 246 which is adapted to turnthe slider 236 of: potentiometer 222. The shaft 246 is also providedwith a number of cams 248-256 which are so designed as to successivelyactuate microswitches 258-266, each of which controls one of theindicators 268276. It will be seen that the number of cams, switches,and indicators depends on the number of different charges which areexpected to be made for the services under consideration. A stop 278 onshaft 246 engaging a fixed member 280 prevents further rotation of shaft246 after the last switch 266 has been actuated.

In operation, the timer 10, through the intermediary of switches 42 and66, at any given time shorts out certain resistors in the resistor banks202 and 206. When a reading operation is to be performed, a card 54 isinserted in the sensing device 100, and as a result certain otherresistors in banks 204 and 206 are shorted out during the readingoperation. The resistors of the banks 202, 204 and 206 remaining in thecircuit at that time have a total resistance proportional to the timeused up in the performance of the services to be measured. Inasmuch asthe resistance 212 is constant, it will be seen that the potentialappearing at wire 226 is an algebraic function of the number ofresistors inseited in the circuit,

'and therefore of the time elapsed. The potential so obtained isfed'into the vibrator 232 and creates a signal which is amplified byamplifier 240 and operates servomotor 244 until such time as theoperation of servomotor 4 244 has turned the potentiometer 222 to thepoint where the potential on wire 234 is the same as the potential onwire 226 and a balance of the input to the vibrator 232 results, so thatno more signal is transmitted to the amplifier 2140.

A device according to our invention in which the punching device and thesensing device are incorporated in the same unit, would then operate asfollows: At the beginning of the time interval desired to be measured, acard 54 is inserted in the punching unit between base plate 56 andsupporting member 52, Figure 2. As the card is advanced to the pointwhere it trips switch '78, solenoid 80 is actuated and, through theintermediary of lever 84, shafts 40 and 63 and selected ones of theplungers 48, two holes are punched into the card 54. The position ofthese holes is then indicative of the time at the beginning of thetimeinterval. Let it be assumed for purposes of illustration that the timeat this moment is 12:34 p.m. The last movement of ratchet 62 hastakenplace at the last full hour which was 12:00. Consequently, arm '74is now in the position where it will punch the plunger 48 in the outercircle corresponding to 12:00. Asratchet 30 is actuated once every hourits last actuation took place at 12:30 which was the end of the lastprevious hour interval. Arm 44 will therefore be in a position where itshead 46 will actuate plunger 48in the inner circle corresponding to Ahour. The marking on the card in this example will therefore consist oftwo holes indicating 12.5 hours.

Let it now be further supposed that the time interval tobe measured endsat 3:15 p.m. At that time card 54'is inserted between base plate 108and, barrel 102 of sensing device 100. As card 54 is fully inserted intothe sensing device it trips switch 112 and thereby causes theenergization of solenoid 114 which by means of arm 118 brings barrel 102containing sensing rings 104 and 106 down on card 54. At the same timesolenoid 122 is energized and by means of lever arm 124 brings stop 120down onto card 54 so as to prevent withdrawal of card 54 until thereading operation is completed. A delay relay 116 is provided forreleasing solenoid 114 after approximately three seconds which is theapproximate time required for a complete reading to be made. Isasmuch ascard 54 has holes punched in it which correspond to 12.5 hours, thecontact fingers of sensing rings 104 and 106 will remain insulated frombase plate 108 except for the fingers corresponding to 12 hours and hourwhich through the holes in the card 54 will come in contact with baseplate 108. A circuit will consequently be closed from the 12-hourscontact finger of sensing ring 106, which is connected to point 282 onresistor bank 206, through the base plate 105 to point 284 between banks204 and 206, and also from the hour contact finger on sensing ring 104,which is connected to point 285 on bank 204, through base plate 103' tothe same point 284. At the same time, the passage of time has advancedswitch 66 to the l5-hours (i.e. 3 p.m.) position Where it connects point228 to point 286 on resistor bank 206, and switching device 42 has cometo the -hour position in which it connects point 288 to point 290 onresistor bank 202.

If the voltage of the DC. supply 216 is E volts, the potential on wire226 With respect to. point 214 will now be E X resistance of resistor212 E total resistance now in 202, 204, 206, and 212 136 as it will beseen from Figure 4 that in this condition two one-unit resistors areactive in bank 202, four oneunit resistors in bank 204, and threeten-unit resistors in bank 206. It will be recalled that resistor 212has been on Wire 234 with respect to point 214 will then be E volts. ADC. signal of will therefore appear across the input to vibrator 232 assoon as relay 126 closes contacts 230. This signal is converted to A.C.,amplified, and fed in a first phase to servomotor 244, which thereuponstarts to turn in a first direction. When the motor 244 has rotatedshaft 246 sufficiently to move the slider of potentiometer 222 to apoint where the voltage picked 01% at point 236 is there will be no moresignal at the input to vibrator 232, and consequently the servomotorwill stop.

If servomotor 244 should overshoot the null point, the polarity of theDC. voltage at the input of vibrator 232 would be reversed, and the A.C.signal delivered to amplifier 240 would be shifted in phase by 180. Thiswould cause the servomotor to turn in the opposite direction and thusreturn to the null point.

When a reading has been completed, delay relay 116 closes, whereuponrelay 126 is de-energized and contacts 230 open. As this prevents anyfurther signal from appearing at the input to vibrator 232, servomotor244 will remain in the position in which it was when contacts 230opened, until the next reading. If, now, cams 248--256 are so cut thatwhen motor 244 drops in our example, switch 262 is closed and all otherswitches 258-266 are open, then indicator 272 will be energized. Ifindicator 272 is arranged, for example, to illuminate an indicator panelon which is marked the price to be charged for 2.7 hours of the service,such as, in our example, $0.90, then the actuation of indicator 272 willbe indicative of the charge to be made.

The embodiment of our invention which has been described above isparticularly adapted for use in a parking lot where cars do not remainovernight. As a result, the full hour at the time of read-out willalways be equal to or later than the hour punched on the card 54, thusavoiding a negative reading, which would give a wrong indication. If itis desired to use our device for multi-day parking such as in hotel orairport garages, or for other uses, our device can readily be adaptedtherefor by the use of additional switches, sensing rings, and resistorbanks.

It will be evident from the foregoing that the system of our inventioncan be carried out in many diiferent embodiments, of which the foregoingdescription is only one example. For example, whereas the devicedescribed above uses the method of punching a card in order to producean indication thereon, it would be equally possible to mark the cardwith a conductive material such as, for example, graphite or aluminumpowder so that the contact fingers can establish an electrical circuitthrough such markings or the card may be blackened in appropriate placesby the application of ink. In the latter case, photocells adapted todetect such markings on a card by photo-electric means couldadvantageously be used to replace the contact fingers in the readingoperation, the photocells being so connected that the appearance of amark within the field of vision of a photocell would result in theclosing of any well-known electronic switching means or relay. It istherefore intended to cover herein all embodiments of this inventionwhich volts fulfill the function of this device within the spirit of theappended claims.

Having thus described the invention, what is claimed and desired to besecured by Letters Patent is:

1. A time-cost computer comprising a bank of resistors connected inseries across a fixed voltage source, a timer, a sensing device, meansoperated by said timer for shortcircuiting selected ones of saidresistors, said sensing de vice being arranged to short-circuit selectedother ones of said resistors in response to coded information introducedinto the computer, a variable voltage source, a nullseekingservomechanism arran ed to vary the voltage of said variable voltagesource, an amplifier for amplifying the voltage difference between saidvariable voltage and the voltage appearing across a predeterminedportion of said resistor bank, a plurality of indicators, and meanscontrolled by said servomechanism and calibrated in terms of cost perunit time for selectively energizing one of said indicators.

2. A time-cost computer according to claim 1, in which said sensingdevice is adapted to detect holes in a punched card.

37 Apparatus for computing and indicating data which is a predeterminedfunction of the time elapsed between a start time and a finish time,said start time being recorded on a card in the form of indicia havingpositions on the card indicative of the time recorded, comprising: aplurality of sensing means arranged to be selectively activated by saidindicia in accordance with the position of said indicia, a plurality ofcircuit components each having a pair of terminals which are normally atdifferent electrical potentials, said circuit components being connectedin series, each of said sensing means being arranged to renderineffective a predetermined number of said circuit components upon beingactivated, clockoperated means for independently rendering ineffective anumber of said circuit components representative of said finish time, acircuit including a potentiometer, a voltage source connected acrosssaid circuit, a null-seeking servomechanism arranged to operate theslide of said potentiometer so as to balance a voltage corresponding tothe position of said slide against the voltage across a predeterminedportion of the chain of said circuit components, and indicating meanscalibrated so as to produce an indication representative of apredetermined function of the position of said slide.

4. Apparatus for computing and indicating data which is a predeterminedfunction of the time elapsed between a start time and a finish time,said start time being recorded on a punched card in the form ofperforations having positions on the card indicative of the timerecorded, comprising: a plurality of sensing means arranged to beselectively closed by said perforations in accordance with the positionof said perforations, a voltage source, a plurality of resistorsconnected in series across said voltage source, each of said sensingmeans being arranged to short-circuit a predetermined number of saidresistors upon being closed, clock-operated switch means forindependently short-circuiting a number of said resistors representativeof said finish time, a circuit including a potentiometer, a voltagesource connected across said circuit, a null-seeking servomechanismarranged to operate the slide of said potentiometer so as to balance thevoltage at said slide against the voltage across a predetermined portionof the chain of resistors, and indicating means calibrated so as toproduce an indication representative of a predetermined function of theposition of said slide.

5. Apparatus according to claim 4, in which said indicating meanscomprise a shaft rotated by said servomechanism in accordance with themovement of said slide, a plurality of cams mounted on said shaft, and aplurality of indicators, each cam being associated with one indicator,and said cams being so disposed on said shaft as to successivelyenergize said indicators as said shaft is rotated.

References Cited in the file of this patent UNITED STATES PATENTS2,659,470 Du Pont Nov. 17, 1953 2,663,497 Straus Dec. 22, 1953 2,732,923Parker Jan. 31, 1956

